Commit 73115d80 authored by Vinod Koul's avatar Vinod Koul
Browse files

Merge tag 'dmaengine_topic_dma_vec' into next 

Dmaengine topic
 - New device_prep_peripheral_dma_vec, documentation and user
parents f8f530ba 380afccc

Documentation/driver-api/dmaengine/client.rst

+9 −0
Original line number Diff line number Diff line
@@ -80,6 +80,10 @@ The details of these operations are: 


  - slave_sg: DMA a list of scatter gather buffers from/to a peripheral



  - peripheral_dma_vec: DMA an array of scatter gather buffers from/to a

    peripheral. Similar to slave_sg, but uses an array of dma_vec

    structures instead of a scatterlist.



  - dma_cyclic: Perform a cyclic DMA operation from/to a peripheral till the

    operation is explicitly stopped.
@@ -102,6 +106,11 @@ The details of these operations are: 
		unsigned int sg_len, enum dma_data_direction direction,

		unsigned long flags);



     struct dma_async_tx_descriptor *dmaengine_prep_peripheral_dma_vec(

		struct dma_chan *chan, const struct dma_vec *vecs,

		size_t nents, enum dma_data_direction direction,

		unsigned long flags);



     struct dma_async_tx_descriptor *dmaengine_prep_dma_cyclic(

		struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,

		size_t period_len, enum dma_data_direction direction);

Documentation/driver-api/dmaengine/provider.rst

+10 −0
Original line number Diff line number Diff line
@@ -433,6 +433,12 @@ supported. 
    - residue: Provides the residue bytes of the transfer for those that

      support residue.



- ``device_prep_peripheral_dma_vec``



  - Similar to ``device_prep_slave_sg``, but it takes a pointer to a

    array of ``dma_vec`` structures, which (in the long run) will replace

    scatterlists.



- ``device_issue_pending``



  - Takes the first transaction descriptor in the pending queue,
@@ -544,6 +550,10 @@ dma_cookie_t 
- Not really relevant any more since the introduction of ``virt-dma``

  that abstracts it away.



dma_vec



- A small structure that contains a DMA address and length.



DMA_CTRL_ACK



- If clear, the descriptor cannot be reused by provider until the

drivers/dma/dma-axi-dmac.c

+40 −0
Original line number Diff line number Diff line
@@ -620,6 +620,45 @@ static struct axi_dmac_sg *axi_dmac_fill_linear_sg(struct axi_dmac_chan *chan, 
	return sg;

}



static struct dma_async_tx_descriptor *

axi_dmac_prep_peripheral_dma_vec(struct dma_chan *c, const struct dma_vec *vecs,

				 size_t nb, enum dma_transfer_direction direction,

				 unsigned long flags)

{

	struct axi_dmac_chan *chan = to_axi_dmac_chan(c);

	struct axi_dmac_desc *desc;

	unsigned int num_sgs = 0;

	struct axi_dmac_sg *dsg;

	size_t i;



	if (direction != chan->direction)

		return NULL;



	for (i = 0; i < nb; i++)

		num_sgs += DIV_ROUND_UP(vecs[i].len, chan->max_length);



	desc = axi_dmac_alloc_desc(chan, num_sgs);

	if (!desc)

		return NULL;



	dsg = desc->sg;



	for (i = 0; i < nb; i++) {

		if (!axi_dmac_check_addr(chan, vecs[i].addr) ||

		    !axi_dmac_check_len(chan, vecs[i].len)) {

			kfree(desc);

			return NULL;

		}



		dsg = axi_dmac_fill_linear_sg(chan, direction, vecs[i].addr, 1,

					      vecs[i].len, dsg);

	}



	desc->cyclic = false;



	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);

}



static struct dma_async_tx_descriptor *axi_dmac_prep_slave_sg(

	struct dma_chan *c, struct scatterlist *sgl,

	unsigned int sg_len, enum dma_transfer_direction direction,
@@ -1061,6 +1100,7 @@ static int axi_dmac_probe(struct platform_device *pdev) 
	dma_dev->device_tx_status = dma_cookie_status;

	dma_dev->device_issue_pending = axi_dmac_issue_pending;

	dma_dev->device_prep_slave_sg = axi_dmac_prep_slave_sg;

	dma_dev->device_prep_peripheral_dma_vec = axi_dmac_prep_peripheral_dma_vec;

	dma_dev->device_prep_dma_cyclic = axi_dmac_prep_dma_cyclic;

	dma_dev->device_prep_interleaved_dma = axi_dmac_prep_interleaved;

	dma_dev->device_terminate_all = axi_dmac_terminate_all;

include/linux/dmaengine.h

+33 −0
Original line number Diff line number Diff line
@@ -160,6 +160,16 @@ struct dma_interleaved_template { 
	struct data_chunk sgl[];

};



/**

 * struct dma_vec - DMA vector

 * @addr: Bus address of the start of the vector

 * @len: Length in bytes of the DMA vector

 */

struct dma_vec {

	dma_addr_t addr;

	size_t len;

};



/**

 * enum dma_ctrl_flags - DMA flags to augment operation preparation,

 *  control completion, and communicate status.
@@ -910,6 +920,10 @@ struct dma_device { 
	struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)(

		struct dma_chan *chan, unsigned long flags);



	struct dma_async_tx_descriptor *(*device_prep_peripheral_dma_vec)(

		struct dma_chan *chan, const struct dma_vec *vecs,

		size_t nents, enum dma_transfer_direction direction,

		unsigned long flags);

	struct dma_async_tx_descriptor *(*device_prep_slave_sg)(

		struct dma_chan *chan, struct scatterlist *sgl,

		unsigned int sg_len, enum dma_transfer_direction direction,
@@ -973,6 +987,25 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_single( 
						  dir, flags, NULL);

}



/**

 * dmaengine_prep_peripheral_dma_vec() - Prepare a DMA scatter-gather descriptor

 * @chan: The channel to be used for this descriptor

 * @vecs: The array of DMA vectors that should be transferred

 * @nents: The number of DMA vectors in the array

 * @dir: Specifies the direction of the data transfer

 * @flags: DMA engine flags

 */

static inline struct dma_async_tx_descriptor *dmaengine_prep_peripheral_dma_vec(

	struct dma_chan *chan, const struct dma_vec *vecs, size_t nents,

	enum dma_transfer_direction dir, unsigned long flags)

{

	if (!chan || !chan->device || !chan->device->device_prep_peripheral_dma_vec)

		return NULL;



	return chan->device->device_prep_peripheral_dma_vec(chan, vecs, nents,

							    dir, flags);

}



static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_sg(

	struct dma_chan *chan, struct scatterlist *sgl,	unsigned int sg_len,

	enum dma_transfer_direction dir, unsigned long flags)